Piston-grinding jig



May 13, 1924. 1,494,244

A. T. HOAGLAND PISTON GRINDING JIG Filed April 8. 1922 IIIIIIIIII) INVENTOR fllberZZT-Jfoa ylaled 4 TTORNE Y8 WITNESSES Patented May 13, 13%24.

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tiara ALBERT T. HOAGLAND, 0J3 BROOKLYN, NEW YORK.

PISTON GRINDI1\TG- JIG.

Application filed April 8,

To all whom it may concern:

Be it known that I, ALBERT T. IIOAGLAND, a citizen of the United States, and a resident of Brooklyn, borough of Brooklyn, in the county of Kings and State of New York, have invented a new and Improved Piston- Grrinding Jig, of which the following is a full, clear, and exact description.

This invention relates to a machine for grinding pistons and particularly to an im proved jig for holding the piston during a grinding operation. An object of the inven- 'tion is to provide an improved, simple and the invention, the same being shown in con nection with a piston and connecting rod.

Figure 2 is a sectional view through Figure 1, approximately on line 22.

Figure 3 is an end view on an enlarged scale of the jig shown in Figure 1.

Figure i is a sectional view on an enlarged scale, said section being taken on line 4. i of Figure 1.

Figure 5 is a plan view of an adapter used in connection with the jig shown in Figure 1.

Figure 6 is an edge view of the structure shown in Figure 5.

Referring to the accompanying drawings by numeral, 1 indicates a piston of any desired kind, said piston being provided with a pin 2 of the usual construction which connects the piston with a connecting rod 3, which connecting rod is providedwith the usual structure i for connecting with the crank shaft of the engine. Heretofore when the pistons have been turned down, for instance on a. lathe, the pin 2 is inserted after the turning down operation has been performed. When this is done the pin2 must be very accurately fitted or the parts again turned down. A. number of efforts have been made to take care of the fitting of the pin 2 when the piston is first manufactured or after the same has been turned down, in order that the grindingoperation may be 1922. Serial No. 550,667.

properly done without affecting either the pin or the piston. In the present invention a jig has been provided which will hold the parts in proper position so that the piston and pin may be ground. together or, if desired, turned down together. The jig em bodying the invention is, however, more particularly adapted for holding the piston properly while being ground in the usual manner. hen it is desired to grind the piston shown in the accompanying drawings it is merely necessary to fit the piston either against the shoulder 5, formed on the end 6, or to fit the same against one of the shoulders 7 of the member 8, which may be termed an adapter. This adapter, as shown in Figures 5 and (3, is provided with an opening 9, which opening registers with the opening 10 in the end 6. The end 6 is provided with integral arms 11, said arms being provided with feet 12 and 13, in which the ends of the screws 14 and 15 are rotatably positioned. Each of the feet 19. and 13 is provided with a pair of standards 16 and 17, which standards extend to and are preferably formed integral with an end plate 18, said plate in the accompanying drawing being shown round, but if desired the same could be formed of some other shape. Each of the screws 14.- and 15 is provided with a traveling nut 19, which when held against rotation will move longitudinally of the screws when said screws are rotated. A cross-bar 20 is provided, said cross-bar having bifurcated ends 21 and 22 straddling the screws 14: and 15 when. in use. This cross-bar is inserted through the crank opening structure 1 and then the parts are positioned as shown in Figure 1., after which the screws 14 and 15 are rotated by a wrench engaging and operating the heads 23 and 24;. This rotation will cause the nuts 19 to move longitudinally of the screws and consequently pull against the bar 20 until the piston 1 is pressed firmly against one of the shoulders 7 in the adapter 8. As soon as the piston has been thus accurately positioned it may be freely rotated by gasping the handle or grip 25 and rotating the disk 18, which movement will be communicated directly to the piston for providing the desired grinding action. It will be noted that the connecting rod 3 may be inserted through the openings 9 and 10 so as to position the rod properly for engagement by bar 20. This side positioning of connecting and the other in the rod permits the piston to be properly mounted on the adapter 8 without removing the pin 2. By providing different shoulders on the adapter 8, difi erent sized pistons may be readily held in the jig for proper grinding. and if desired the different size adapters 8 may be used without departing from the spirit of the invention.

The jig is adapted to be supported between two centers when in use and then rotated so that a cutting tool or grinding tool may be caused to act upon the piston. Suitable centering depressions A and B are provided, one being in the piston as is usual These depressions are designed to receive centeringpins on a lathe or other turning device. here theig and piston are mounted on the lathe, the handle or grip 25 may be rotated manually or may be engaged by a dog connected to the face plate on the lathe. lVhen the device is mounted on a lathe and operated thereby, the ordinary cutting tools of the lathe may be used for turning down the piston. It preferred, grinding wheel might be used on the usual tool rest of the lathe or may beheld against the piston manually by the ope 'ator. Heretofore, it has been necessary to disconnect the pin 2 and associated parts so that only the shell of the piston is left and the open end is usually gripped by a chuck in the lathe with the recess in the closed end accommodating a centering pin on the tail stock of the lathe. When the piston is mounted in a lathe in the manner just described, it necessitates a large amount of work in dismantling the parts and then reassembling the same. By providing the disclosed in the drawing, the connecting rod 2- and the pin 2 may not be removed and notwithstanding this fact, the piston is held by the jig so as to be centered in a lathe or any other machine and positioned to be turned so that a cutting tool or grinding tool may be forced against the same by any mechanism.

\Vhat I claim is:

1. A grinding of the charm-ter described, comprising an end member having a central bore merging into a side notch whereby a piston mounted on said end may have its connecting rod passed through said notch into said bore without disconnecting from said piston, a tension bar extending through the end of said connecting rod opposite the end connected with the piston, a pair of threaded members extending past said tension bar and travelingnuts arranged on said threaded members adapted to act on the tension bar for bringing. the same under tension and thereby cause said piston to bc clamped against said end.

2. In a for holding pistons during the grinding operation, comprising an end member having a central bore and a notch radiating therefrom, a pair of standards ex tending from said end member, a second end member rigidly connected with said standard at the end opposite the first mentioned end member, a pair of bars rotatably mounted in said end, said .bars between the end members being threaded, a traveling nut mounted on each of the end members and formed in such shape as to engage said standards when the bars are rotated so that they will travel longitudinally of the bars, and a tension bar formed with the end straddling said threaded bars, said tension bar being adapted to engage a connecting rod for clamping the piston to said body.

3. In a for holding pistons during the grinding operation, comprising a plurality of pairs of standards, a threaded bar arranged between each pair of standards and extending parallel therewith, a pair of end members rigidly connected with the respective ends of said pairs of standards, said threaded bars being rotatably mounted in said end members, a nut arranged on each of said threaded bars formed rectangularly and of such size so as to be engaged by such standards and held against rotation as the threaded bars rotate, thus causing a longitudinal movement of said traveling members, a tension bar arranged with its ends engaging said traveling members, whereby it is moved as said threaded bars are rotated, one of said ends being provided with a central bore, an opening extending to the periphery of said ends merging into said bore, whereby a piston may be fitted against said end and the connecting rod passed into said bore Without disconnecting the piston and connecting :rod.

4. In a grinding :tor pistons, a body structure formed with an end having a substantial annular shoulder, a central bore and a notch radiating from said bore to the interior of the end, an adapter litting said annular shoulder provided with an opening registering with said notch, and a plurality of substantially annular piston receiving shoulders and means carried by said body for clamping the piston against one of said annular shoulders, said notches permitting the connecting rod of the piston to be inserted into'said bore without disconnection from the piston.

ALBERT T. :HOAGLAND. 

